And I turned around and asked where Polemarchus might be. "There," he said, "he is coming behind; just wait."
"Certainly, we will wait," said Glaucon.
[Three things here.
(1) Do people still ask where someone "might be"? Or is it better to ask where someone "is"? S. uses the optative case to inquiry into the whereabouts of P., which is literally translated "might be." That might sound foreign and/or highfalutin to some, but I like it.
(2) The name "Polemarchus" does not actually occur in the text here. There is only the verb "he might be" and the reflexive "himself" so that the reader knows S. is inquiring after P. and not, for some odd reason, the slave boy standing in front of him. But translating "he himself" seemed awkward.
(3) The last sentence is a hodgepodge of particles and pronouns. Cornford translates: "'Very well,' said Glaucon, 'we will.'" There seems to be a slight difference between this and Bloom's "Of course we will wait." Cornford's offers the possibility that G. is reluctant to wait; Bloom's makes G. sound a bit eager to wait for P. (This could be an attempt to show off Glaucon's eagerness; cf. 357a.) I couldn't find anything one way or the other in LSJ or Smyth on the particular construction used here, so I tried to strike a middle ground with the colloquial "certainly."]